On the left Bottom is the normal Horn formation of a Waterbuck and on the Top right is the abnormality.
Horn abnormalities are presumed to be caused by Genetic issues ie: In breeding due to a lack of sufficient gene pools.
In all game reserves this can be found where numbers of a species are so low that in breeding occurs.
This is “common” in cases where a species are dependant on water or Forrest lands etc. If this is not available then abnormalities can occur.
Sometimes during Birth, the foul can fall heavily on its head and this could cause a twist of the area where the Horns develop from.
All in all it is very interesting and this picture above was taken by a guest on a recent tour to Hluhluwe / Imfolozi game reserve.